<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.aaa{
				position: absolute;
				margin: auto;
				top: 0;
				bottom: 0;
				left: 0;
				right: 0;
				
				width: 100px;
				height: 350px;
				background: pink;
			}
		</style>
	</head>
	<body>		
		<!-- CSS 垂直+左右同时居中  -->
		<div class="aaa"></div>
	</body>
</html>